[PATCH] D79265: Let normalize() for posix style convert backslash to slash unconditionally.

[Nico Weber via Phabricator via llvm-commits]

thakis created this revision.
thakis added a reviewer: compnerd.
Herald added a subscriber: hiraditya.
Herald added a project: LLVM.

Currently, normalize() for posix replaces backslashes to slashes, except
that two backslashes in sequence are kept as-is.

clang calls normalize() to convert \ to / is microsoft compat mode. This
generally works well, but a path like "c:\\foo\\bar.h" with two
backslashes doesn't work due to the exception in normalize().

These paths happen naturally on Windows hosts with e.g.
`#include __FILE__`, and them not working on other hosts makes it
more difficult to write tests for this case.

The special case has been around without justification since this code
was added in r203611 (since then moved around in r215241 r215243).  No
integration tests fail if I remove it.

Try removing the special case.


https://reviews.llvm.org/D79265

Files:
  clang/test/Lexer/case-insensitive-include-ms.c
  llvm/lib/Support/Path.cpp
  llvm/unittests/Support/Path.cpp


Index: llvm/unittests/Support/Path.cpp
===================================================================
--- llvm/unittests/Support/Path.cpp
+++ llvm/unittests/Support/Path.cpp
@@ -1182,7 +1182,7 @@
   Tests.emplace_back("a", "a", "a");
   Tests.emplace_back("a/b", "a\\b", "a/b");
   Tests.emplace_back("a\\b", "a\\b", "a/b");
-  Tests.emplace_back("a\\\\b", "a\\\\b", "a\\\\b");
+  Tests.emplace_back("a\\\\b", "a\\\\b", "a//b");
   Tests.emplace_back("\\a", "\\a", "/a");
   Tests.emplace_back("a\\", "a\\", "a/");
 
Index: llvm/lib/Support/Path.cpp
===================================================================
--- llvm/lib/Support/Path.cpp
+++ llvm/lib/Support/Path.cpp
@@ -539,17 +539,11 @@
       PathHome.append(Path.begin() + 1, Path.end());
       Path = PathHome;
     }
-  } else {
-    for (auto PI = Path.begin(), PE = Path.end(); PI < PE; ++PI) {
-      if (*PI == '\\') {
-        auto PN = PI + 1;
-        if (PN < PE && *PN == '\\')
-          ++PI; // increment once, the for loop will move over the escaped slash
-        else
-          *PI = '/';
-      }
-    }
+    return;
   }
+  for (auto PI = Path.begin(), PE = Path.end(); PI < PE; ++PI)
+    if (*PI == '\\')
+      *PI = '/';
 }
 
 std::string convert_to_slash(StringRef path, Style style) {
Index: clang/test/Lexer/case-insensitive-include-ms.c
===================================================================
--- clang/test/Lexer/case-insensitive-include-ms.c
+++ clang/test/Lexer/case-insensitive-include-ms.c
@@ -6,15 +6,17 @@
 // RUN: %clang_cc1 -fsyntax-only -fms-compatibility %s -include %s -I %t/Output -verify
 // RUN: %clang_cc1 -fsyntax-only -fms-compatibility -fdiagnostics-parseable-fixits %s -include %s -I %t/Output 2>&1 | FileCheck %s
 
-// FIXME: Add a test with repeated backslashes once clang can handle that
-// in ms-compat mode on non-Windows hosts.
 #include "..\Output\.\case-insensitive-include.h"
 #include "..\Output\.\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
 // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:50}:"\"..\\Output\\.\\case-insensitive-include.h\""
+#include "..\\Output\.\\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:52}:"\"..\\\\Output\\.\\\\case-insensitive-include.h\""
 #include "..\output\.\case-insensitive-include.h" // expected-warning {{non-portable path}}
 // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:50}:"\"..\\Output\\.\\case-insensitive-include.h\""
 
 #include "apath\..\.\case-insensitive-include.h"
 #include "apath\..\.\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
 // CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:49}:"\"apath\\..\\.\\case-insensitive-include.h\""
+#include "apath\\..\\.\\Case-Insensitive-Include.h" // expected-warning {{non-portable path}}
+// CHECK: fix-it:"{{.*}}":{[[@LINE-1]]:10-[[@LINE-1]]:52}:"\"apath\\\\..\\\\.\\\\case-insensitive-include.h\""
 #include "APath\..\.\case-insensitive-include.h" // For the sake of efficiency, this case is not diagnosed. :-(


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D79265.261536.patch
Type: text/x-patch
Size: 3093 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20200502/9eb89394/attachment.bin>